The Old Ones were an authority to whom Korob and Sylvia owed some form of duty or fealty. Presumably, they sent the two explorers to Pyris VII to learn. Korob reminds Sylvia of this duty, but she has become intoxicated by sensation (something that does not exist where she and Korob are from), and rejects his opinion that her actions are not in accord with her responsibilities.
The Old Ones made several mistakes. They gave Korob, the senior member of their exploration team, a more powerful transmuter, but failed to realize that he lacked the will to use that power, even when his colleague Sylvia became irrational. They failed to realize the dangers of being immersed in sensation (the cause of Sylvia's irrationality). (TOS: "Catspaw")
- The Old Ones either did not, or could not, monitor their explorers, or presumably they would have intervened before Sylvia became so dangerous, or to save the lives of their people after Kirk smashed the transmuter.